mixer.h File Reference

Multi-Source Audio Mixing and Processing System. More...

Go to the source code of this file.

Data Structures
struct	compressor_t
	Dynamic range compressor settings and state. More...
struct	noise_gate_t
	Noise gate settings and state. More...
struct	highpass_filter_t
	High-pass filter settings and state. More...
struct	lowpass_filter_t
	Low-pass filter state. More...
struct	ducking_t
	Ducking system settings and state. More...
struct	mixer_t
	Main mixer structure for multi-source audio processing. More...

Macros
Audio Mixing Configuration
#define	MIXER_MAX_SOURCES   32
	Maximum number of simultaneous audio sources.
#define	MIXER_FRAME_SIZE   256
	Number of samples processed per audio frame.

Functions
Mixer Lifecycle Functions
mixer_t *	mixer_create (int max_sources, int sample_rate)
	Create a new audio mixer.
void	mixer_destroy (mixer_t *mixer)
	Destroy a mixer and free all resources.
Source Management Functions
int	mixer_add_source (mixer_t *mixer, uint32_t client_id, audio_ring_buffer_t *buffer)
	Add an audio source to the mixer.
void	mixer_remove_source (mixer_t *mixer, uint32_t client_id)
	Remove an audio source from the mixer.
void	mixer_set_source_active (mixer_t *mixer, uint32_t client_id, bool active)
	Set whether a source is active (receiving audio)
Audio Processing Functions
int	mixer_process (mixer_t *mixer, float *output, int num_samples)
	Process audio from all active sources.
int	mixer_process_excluding_source (mixer_t *mixer, float *output, int num_samples, uint32_t exclude_client_id)
	Process audio from all sources except one (for per-client output)
Utility Functions
float	db_to_linear (float db)
	Convert decibels to linear gain.
float	linear_to_db (float linear)
	Convert linear gain to decibels.
float	clamp_float (float value, float min, float max)
	Clamp a float value to a range.
Compressor Functions
void	compressor_init (compressor_t *comp, float sample_rate)
	Initialize a compressor.
void	compressor_set_params (compressor_t *comp, float threshold_dB, float ratio, float attack_ms, float release_ms, float makeup_dB)
	Set compressor parameters.
float	compressor_process_sample (compressor_t *comp, float sidechain)
	Process a single sample through compressor.
Ducking Functions
int	ducking_init (ducking_t *duck, int num_sources, float sample_rate)
	Initialize ducking system.
void	ducking_free (ducking_t *duck)
	Free ducking system resources.
void	ducking_set_params (ducking_t *duck, float threshold_dB, float leader_margin_dB, float atten_dB, float attack_ms, float release_ms)
	Set ducking parameters.
void	ducking_process_frame (ducking_t *duck, float *envelopes, float *gains, int num_sources)
	Process a frame of audio through ducking system.
Noise Gate Functions
void	noise_gate_init (noise_gate_t *gate, float sample_rate)
	Initialize a noise gate.
void	noise_gate_set_params (noise_gate_t *gate, float threshold, float attack_ms, float release_ms, float hysteresis)
	Set noise gate parameters.
float	noise_gate_process_sample (noise_gate_t *gate, float input, float peak_amplitude)
	Process a single sample through noise gate.
void	noise_gate_process_buffer (noise_gate_t *gate, float *buffer, int num_samples)
	Process a buffer of samples through noise gate.
bool	noise_gate_is_open (const noise_gate_t *gate)
	Check if noise gate is currently open.
High-Pass Filter Functions
void	highpass_filter_init (highpass_filter_t *filter, float cutoff_hz, float sample_rate)
	Initialize a high-pass filter.
void	highpass_filter_reset (highpass_filter_t *filter)
	Reset high-pass filter state.
float	highpass_filter_process_sample (highpass_filter_t *filter, float input)
	Process a single sample through high-pass filter.
void	highpass_filter_process_buffer (highpass_filter_t *filter, float *buffer, int num_samples)
	Process a buffer of samples through high-pass filter.
Low-Pass Filter Functions
void	lowpass_filter_init (lowpass_filter_t *filter, float cutoff_hz, float sample_rate)
	Initialize a low-pass filter.
void	lowpass_filter_reset (lowpass_filter_t *filter)
	Reset low-pass filter state.
float	lowpass_filter_process_sample (lowpass_filter_t *filter, float input)
	Process a single sample through low-pass filter.
void	lowpass_filter_process_buffer (lowpass_filter_t *filter, float *buffer, int num_samples)
	Process a buffer of samples through low-pass filter.
Buffer Utility Functions
float	smoothstep (float t)
	Compute smoothstep interpolation.
int16_t	float_to_int16 (float sample)
	Convert float sample to int16 (WebRTC format)
float	int16_to_float (int16_t sample)
	Convert int16 sample to float.
void	buffer_float_to_int16 (const float *src, int16_t *dst, int count)
	Convert float buffer to int16 buffer.
void	buffer_int16_to_float (const int16_t *src, float *dst, int count)
	Convert int16 buffer to float buffer.
float	buffer_peak (const float *buffer, int count)
	Find peak absolute value in buffer.
void	apply_gain_buffer (float *buffer, int count, float gain)
	Apply gain to buffer in-place.
void	fade_buffer (float *buffer, int count, float start_gain, float end_gain)
	Apply linear fade to buffer in-place.
void	fade_buffer_smooth (float *buffer, int count, bool fade_in)
	Apply smoothstep fade to buffer in-place.
void	copy_buffer_with_gain (const float *src, float *dst, int count, float gain)
	Copy buffer with gain scaling.
Soft Clipping Functions
float	soft_clip (float sample, float threshold, float steepness)
	Apply soft clipping to a sample.
void	soft_clip_buffer (float *buffer, int num_samples, float threshold, float steepness)
	Apply soft clipping to a buffer.

Detailed Description

Multi-Source Audio Mixing and Processing System.

Definition in file mixer.h.